Transition metal-free oxidation of alcohols catalyzed by carbon quantum dots (CQDs) with NaClO oxidant using water as an only solvent was developed. High quality CQDs were synthesized via a simple one-pot electrochemistry method using cheap graphite rod as substrate materials, without the assistance of any chemicals but only pure water. The morphologies and composition of the resulting catalyst were characterized in detail. The results indicated that the CQDs catalyst showed higher activity and selectivity comparing to other carbon based transition metal-free catalyst (such as carbon nanotubes, graphene et al.) in the selective oxidation of alcohols to aldehydes. The high performance of the CQDs can be mainly attributed to its small particle size and large amounts of surface oxygen containing groups. The CQDs catalyst can be reused five times without any significant loss in their catalytic activities.